Whenever you have an Alert, Blackboard will notify you by placing a red flag in your personal menu.
To view your alerts, click the pulldown to reveal the menu.
In the left hand area of the menu, choose the Updates option (it looks like a Clock and has the red alert flag on it).
This will bring you the Updates area of MyBlackboard.
Here you will see all of the recent updates related to courses that you are involved with. You can open these within your course, or you can dismiss the update so that it no longer appears.
To edit which updates you see, click on the GEAR in the upper right corner of the window. This will open the Update Settings window.
Choose which types of updates you want to view and click Save.